Chrome ignores all inputs after multiple “GtkFileChooserDialog” dialogs are opened in parallel.

I’m considering reporting this to the Chrome developers, but first I’d like some input from the Antergos userbase.
Also wanted to ask on the Arch forums, but since they hate Antergos users over there… not sure if I can without lying a bit.

Can anyone reproduce this and report here?
Should I post on the AUR comment section about this?
Should I ask on the Arch forum about it?
Should I report directly to Chrome devs? Chromium devs? Any hints as to what not to say in the bug report?

Chrome will start downloading the file, but the user inputs are not registered anymore (mouse and keyboard alike).

Then, I can still resize, and redraw the window in my window manager (tested in both i3-wm and XFCE’s xfwm), even the download status bar is still updating fine as well. No graphical glitch, except the mouse cursor stuck as “grasping hand” icon (probably unrelated). Clicking anywhere doesn’t do anything and all keyboard inputs are ignored during window focus. The only thing left to do is to kill the Chrome instance.

This bug has also been tested with all extensions disabled (–disable-extensions command line option).
Version tested: package “google-chrome 55.0.2883.87-1” from the AUR.

This also happens in Chromium browser stable Version 55.0.2883.87 (64-bit) (with no extension loaded either)!